// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_BASE_HASH_VALUE_H_
#define NET_BASE_HASH_VALUE_H_

#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include <string>
#include <vector>

#include "base/strings/string_piece.h"
#include "build/build_config.h"
#include "net/base/net_export.h"

namespace net {

struct NET_EXPORT SHA1HashValue {
    unsigned char data[20];
};

inline bool operator==(const SHA1HashValue& lhs, const SHA1HashValue& rhs)
{
    return memcmp(lhs.data, rhs.data, sizeof(lhs.data)) == 0;
}

inline bool operator!=(const SHA1HashValue& lhs, const SHA1HashValue& rhs)
{
    return !(lhs == rhs);
}

struct NET_EXPORT SHA256HashValue {
    unsigned char data[32];
};

inline bool operator==(const SHA256HashValue& lhs, const SHA256HashValue& rhs)
{
    return memcmp(lhs.data, rhs.data, sizeof(lhs.data)) == 0;
}

inline bool operator!=(const SHA256HashValue& lhs, const SHA256HashValue& rhs)
{
    return !(lhs == rhs);
}

enum HashValueTag {
    HASH_VALUE_SHA1,
    HASH_VALUE_SHA256,
};

class NET_EXPORT HashValue {
public:
    explicit HashValue(const SHA1HashValue& hash);
    explicit HashValue(const SHA256HashValue& hash);
    explicit HashValue(HashValueTag tag)
        : tag(tag)
    {
    }
    HashValue()
        : tag(HASH_VALUE_SHA1)
    {
    }

    // Serializes/Deserializes hashes in the form of
    // <hash-name>"/"<base64-hash-value>
    // (eg: "sha1/...")
    // This format may be persisted to permanent storage, so
    // care should be taken before changing the serialization.
    //
    // This format is used for:
    //   - net_internals display/setting public-key pins
    //   - logging public-key pins
    //   - serializing public-key pins

    // Deserializes a HashValue from a string. On error, returns
    // false and MAY change the contents of HashValue to contain invalid data.
    bool FromString(const base::StringPiece input);

    // Serializes the HashValue to a string. If an invalid HashValue
    // is supplied (eg: an unknown hash tag), returns "unknown"/<base64>
    std::string ToString() const;

    size_t size() const;
    unsigned char* data();
    const unsigned char* data() const;

    HashValueTag tag;

private:
    union {
        SHA1HashValue sha1;
        SHA256HashValue sha256;
    } fingerprint;
};

inline bool operator==(const HashValue& lhs, const HashValue& rhs)
{
    return lhs.tag == rhs.tag && memcmp(lhs.data(), rhs.data(), lhs.size()) == 0;
}

inline bool operator!=(const HashValue& lhs, const HashValue& rhs)
{
    return !(lhs == rhs);
}

typedef std::vector<HashValue> HashValueVector;

class SHA1HashValueLessThan {
public:
    bool operator()(const SHA1HashValue& lhs,
        const SHA1HashValue& rhs) const
    {
        return memcmp(lhs.data, rhs.data, sizeof(lhs.data)) < 0;
    }
};

class SHA256HashValueLessThan {
public:
    bool operator()(const SHA256HashValue& lhs,
        const SHA256HashValue& rhs) const
    {
        return memcmp(lhs.data, rhs.data, sizeof(lhs.data)) < 0;
    }
};

// IsSHA256HashInSortedArray returns true iff |hash| is in |array|, a sorted
// array of SHA256 hashes.
bool IsSHA256HashInSortedArray(const SHA256HashValue& hash,
    const uint8_t* array,
    size_t array_byte_len);

} // namespace net

#endif // NET_BASE_HASH_VALUE_H_
